Preheat oven to 350°F (175°C). Grease a 9×5-inch loaf pan or line it with parchment paper.

In a large mixing bowl, mash the bananas until smooth. Stir in melted butter, granulated sugar, and brown sugar until combined.

Add eggs and vanilla extract, mixing well.

In a separate bowl, whisk together flour, baking soda, salt, and cinnamon.

Gradually add dry ingredients to the banana mixture, stirring gently until just combined. Do not overmix.

Fold in sour cream and optional add-ins like walnuts or chocolate chips.

Pour the batter into the prepared loaf pan and smooth the top.

Bake for 55-65 minutes, or until a toothpick inserted into the center comes out clean.

Let the banana bread cool in the pan for 10 minutes before transferring to a wire rack to cool completely.

Slice and enjoy!